The general flow for a cross-chain message goes from an application deployed to chain A, to the Wormhole contract on chain A, to the Guardian network, then submitted to chain B.
To get started and simulate this flow locally, you'll need a local environment to test your xdapp code. To test, we need to be able to deploy some chains, deploy the Wormhole contracts to these chains, and then run at least one Wormhole validator to pick up messages.
Later, we can introduce a relayer to automatically submit messages, though that's currently supported for Mainnet Token Bridge native and stable coin transfers only. Developers currently have to use either a manual relayer method or an app-sepecific relayer (more on that in the Relayer section).
Before we setup an xdapp project, we'll need to choose a local environment to run the Wormhole Guardian Network. We can use either Wormhole Local Validator or Tilt.
- [Wormhole Local Validator](./wormhole-local-validator.md): This is the simplest custom environment. It's BYOB (Bring your own Blockchain), where you can run your own local validator nodes and connect them to a single Guardian running on docker. Initial setup can take upwards of 500 seconds, but after the image is built, bringing it up and down is usually <1minute.Thisenvironmentrequiresinstallingthesoftwareforthevalidatornodeslocallyonyourcomputerorsomewheretorunthem.
- [Tilt](./tilt/overview.md): A full-fledged Kubernetes deployment of *every* chain connected to Wormhole, along with a Guardian node. Usually takes 30 min to spin up fully, but comes with all chains running out of the box.
If you want to test on the various test and devnets of existing connected chains, there's a single Guardian node watching for transactions on various test networks. You can find the contracts [here](../reference/contracts.md) and the rpc node [here](../reference/rpcnodes.md).
Because testnet only has a single Guardian, there's a small chance that your VAAs will not be processed. This rate is *not* indiciative of performance on mainnet, where there are 19 Guardians watching for transactions.
When you're ready to deploy to mainnet, you can find the mainnet contracts [here](../reference/contracts.md) and the mainnet rpc nodes [here](../reference/rpcnodes.md).
